Electrical measuring instrument.



"110,796,053. PATENTEDA'UG. 1, 1906.

ELECTRICAL MEASURING INSTRUMENT.

APPLICATION-FILED AUG. 26, 1901. RENEWED JAN. 7. 1905.

uummum mu I TO MOTOR I WITNESSES." v fNVENTOR TL-IBM 5:31.111 EATLTHOMAS DUNCAN, OF CHICAGO, ILLINOIS.

ELECTRICAL MEASURING INSTRUMENT.

Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed August 26, 1901. Renewed January 7. 1905. Serial No-239,976.

To all whom it may concern.-

Be it known that I, THOMAS DUNoAN, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new'and useful Improvement in Electrical MeasuringInstruments, of which the following is a full, clear,

concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to meters adapted for use in connection 'withstorage batteries, and has for its object the provision of a meter thatis adapted to rotate at different rates of speed per unit of load orenergy upon variations in the rate of battery discharge.

By means of my invention the meter is caused to operate at an increasedrate of speed per unit of load or energy upon an increase in the rate ofdischarge.

In the use of storage batteries it is well known that the output of thebattery will al ways be less than the energy stored therein and that thebattery loss will increase upon asufiicient increase in the rate ofbattery discharge. For example,if the battery is charged one thousandampere hours at its normal rate of chargesay one hundred amperes for tenhoursthe total discharge at the same rate which can be made availablewithout harm to the battery will not be more than about eighty per cent.of the energy charged into the battery with some makes of battery, thisbattery loss varying with dilferent makesthat is, the battery willeffectively operate at one hundred amperes per hour for eight hours,giving out eight hundred ampere-hours after having received onethousand. Ifthe rate of discharge is increased, the total output willbe' diminished. For example, with certain makes of battery the energydischarged will not be over-about seventy per cent. if the rate isincreased to one hundred and forty amperes, sixty per cent. if the rateof discharge is doubled, and

forty per cent. if the rate quadrupled.

I have provided an instrument that is adapted to compensate for thevarying battery losses due to the varying rates of discharge, so thatthe user of the battery may know when the available energy in thebattery is spent. Or-

of discharge is dinarily a meter associated with a storage 'battery thatis discharged at varying rates will indicate the presence of more energyin the battery than actually exists. The meter of my invention is alsoadapted to measure the energy that is being stored in the battery, themeter when thus associated with the charg-' ing source of current beingoperatively dis- I sociated from the means that cause the meter tooperate at varying rates of speed per unit of load or energy atdifferent rates of dis charge.

The meter of my invention is particularly adapted for use in connectionwith motors employed in operating motor-vehicles where the rate ofdischarge is not constant, but is liable to be changed at any time.

In my presentinvention I employ means for producing a variablecompensating torque for producing a variation in the rate of operationof the meter, said means being automatically controlled by means subjectto the variable volume of current flowing from the battery. For thispurpose I prefer to emsistance in circuit with the supplemental wind-ving when the battery discharge is reduced, portions of the resistancebeing excluded when the battery discharge increases, whereby the torqueof the instrument is modified to produce rates of operation of the metercommensurate with varying batterydischarge.

I will explain my invention more fully .by reference to the accompanyingdrawing, which is a diagrammatic view of a storagebattery system withthe meter of my invention associated therewith.

In the drawing a storage battery 1 is illustrated having mains 2 and 3.The main 2 is provided with bifurcated branches 4 5, terminating incontacts 6 and 7, while the main 3 terminates in a pivotal mounting 8,upon which a switch-blade 9 of a switch 10 is secured. A secondswitch-blade 11 of the switch 10 is also placed upon a pivotal mounting12. Terminals of a charging-circuit 13 and 14. are illustrated.Terminals 15 and 16 of conductors leading to translating means, as themotor of a motor-vehicle, are also illustrated.

When the switch 10 is thrown to the left, the charging-machine or sourceof current is thrown into circuit with the storage battery. When theswitch is thrown to the right, the storage battery is thrown intocircuit with the translating means.

1 have illustrated a meter having a currentwinding included in the main2, this currentwinding being subdivided into coils 17 17. The meter isalso provided with a pressurewinding 18, included in bridge between thebattery leads or mains. These windings of the meter are constantly incircuit with the battery irrespective of its association with thebharging machine or the translating means. The meter-winding 18 ispreferably in the form of an armature and is mounted upon a spindle 19,at the lower end of which is provided a disk 20, arranged within thefields of damping-magnets 21 22. The shaft 19 also carries thecommutator 23, against which bear brushes 24c 24:, that serve to includethe armature of the meter in circuit, a choking resistance 25 being alsoincluded in circuit with the armature.

The meter is provided with gearing at its upper end to actuate themeasuring-index 26, which by cooperation with a suitable readingscaleserves to indicate the amount of energy stored in the batteryin chargingand remaining in the batteryin discharging. The meter illustrated isadapted to measure in units of kilowatt-hours.

The meter is provided with a supplementalpressure winding divided intostationary coils 27 27, this being the form of supplementalmeter windingI prefer to employ. A rheostat resistance 28 is included in series withthe coils 27 27. A solenoid 29, controlling the rhoestatarm is includedin the branch conductor 5. Upon an increase in the battery discharge thestrength of this magnet is increased and resistance of the rheostat cutout of circuit. Upon a decrease in the battery discharge the magnet isweakened and resistance cut into circuit with the winding 27. In thismanner the speed of the meter is changed per unit of load or energyaccording to the degree of battery discharge. The winding 27 is providedwith terminals 27 27, which engage the blades of the switch 10 only whenthe battery is connected with the translating means, this supplementalwinding being removed while the battery is being charged.

When the switch is thrown to the right, the branch conductor 4 isdisconnected, whereupon the meter-circuit is completed by way of theconductor 5.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination with a storage battery, of a meterreceiving current therefrom, and means for varying the strength of thefield due to a Winding operated by the current flowing from the batteryand varying in its operation according to the rate of battery discharge,

whereby the rate of operation of the meter.

per unit of load or energy may be varied according to the varied batterydischarge, sul stantially as described.

2. The combination with a storage battery, of a meter receiving currenttherefrom, a rheostat included in circuit with a meter-winding,

and an electromagnetic device in series with the battery serving,according to the rate of battery discharge, to include more or less ofthe resistance of the rheostat in circuit with said meter-winding tocompensate for variation in battery discharge, substantially asdescribed.

3. The combination with a storage battery, of a meter receiving currenttliere'lron'n'a rheostat included in circuit with a meter-winding, andan electromagnetic device in series with the battery and serving,according to the battery discharge, to include more or less of theresistance of the rheostat in circuit with said meter-winding tocompensate for variation in battery discharge, the said meter-windingbeing subject to the pressure of the battery, substantially asdescribed.

4:. The combination with a storage battery,

of a meter receiving currenttherefrom, a supplemental winding for themeter. a rheostat included in circuit with said supplemental winding,and an electromagnetic device in series with the battery and servingaccording to the rate of battery discharge to include more or less ofthe resistance of the rheostat in circuit with said meter-winding tocompensate for variation in battery discharge, substantially asdescribed.

5. The combination with a storage battery, of a meter receiving currenttherefrom, a supplemental-pressure winding for the meter, a rheostatincluded in circuit with said supplemental winding. and anelectromagnetic device in series with the battery and serving, accordingto the rate of battery discharge, to include more or less of theresistance of the rheostat in circuit with said meter-winding tocompensate for variation in battery discharge, substantially asdescribed.

6. The combination with a storage battery, of a meter receiving currenttherefrom, a supplemental winding for the meter, a rheostat included incircuit with said supplemental winding, an electromagnetic device inseries with the battery and serving, according to the rate of batterydischarge, to include more or less of the resistance of the rheostat incircuit with said meter-winding to compensate for variation in batterydischarge, and a switching device for including the said su 'iplementalwinding in circuit when the battery is connected with the translatingmeans and excluding the same from circuit when the battery is connectedwith the charging-circuit, substantially as described.

7. The combination with a storage battery, of a meter receiving currenttherefrom, a supplemental-pressure winding for the meter, a rheostatincluded in circuit with said supplemental winding, an electromagneticdevice in series with the battery and serving, according to the rate ofbattery discharge, to include more or less of the resistance of therheostat. in circuit with said meter-winding to compensate for variationin battery discharge, and a switching device for including the saidsupplemental winding in circuit when the battery is connected with thetranslating means and excluding same from circuit when the battery isconnected with the charging-circuit, substantially as described. 8. Thecombination with a storage battery,

' of a meter receiving current therefrom, and

means for varying the strength of the field due to a winding operated bythe current flowing from the battery and varying in its operationaccording to the rate of battery discharge, substantially as described.

9. The combination with a storage battery, of a meter receiving currenttherefrom, a rheostat included in circuit with a meterwinding, and anelectromagnetic means in series with the battery serving, according tothe rate of battery discharge, to include more or less of the resistanceof the rheostat in circuit with said meter-winding to compensate forvariation in battery discharge, substantially as described.

10. The combination with a storage battery, of a meter receiving currenttherefrom, a rheostat included in circuit with a meterwinding, and anelectromagnetic means, serving to include more or less of the resistanceof the rheostat in circuit with said meterwinding to compensate forvariation in battery discharge, substantially as described.

11. The combination with a storage battery, of a meter to measure thecurrent passing through the battery, means for varying the rate ofoperation of said meter per unit of load or energy, and electromagneticmeans in series with the battery to control the variation in the rate ofoperation of the said meter, substantially as described.

12. The combination with a storage battery,

meter per unit of load or energy, substantially v as described.

13. The combination with a storage battery, of a meter provided withcurrent and pressure windings, means for varying the field due to one ofsaid windings, and electromagnetic means in series with the battery tobe thereby subject to the varying current discharged from the battery,to vary the torque according to the rate of battery discharge to corre-.spondingly alter the rate of operation of the meter per unit of load orenergy, substantially as described.

14:. The combination with a storage battery, of a meter provided withcurrent and pressure windings, means for varying the field due to one ofthe said windings, and electromagnetic means in series with the batteryto be thereby subject to the varying current discharged from thebattery, to control the variation in the field due to one of saidwindings to correspondingly alter the rate of operation of the meter perunit of load or energy, substantially as described.

In Witness whereof I hereunto subscribe my name this 16th day of August,A. D. 1901..

THOMAS DUNCAN.

Witnesses:

GEORGE L. ORAGG, HERBERT F. OBERGFELL.

